Description: River and lake sediments from the Aberjona Valley have been shown to mutate human cells in short term assays. The chemical responsible for most of the mutagenicity of the organic sediment phase has been identified as benzo(a)pyrene. Its abundance correlates well with the local use of coal for home heating over the past century. The inorganic chemical mutagenicity of sediments of the Aberjona is however much greater than the organic group. Most of this activity may be ascribed to chromate deposited after two major releases circa 1930 and 1960 from the Aberjona headwater in and about the present Industriplex Superfund Site. Humans are usually exposed to water-borne chemicals at concentrations low enough to justify an assumption of independent action. This is claimed not to be the case for our estimate for chromate (4muM) and arsenite (1muM) in East Woburn drinking water drawn from municipal wells G and H. Thus, the intention is to examine the mutagenic results of arsenite interaction with chromate and other mutagens. Furthermore, human body water concentrations would be significantly lower than drinking water levels. They therefore consider it necessary to examine the mutagenicity of the sediments' chemicals at concentrations covering the range expected for children from birth to adolescence. In addition, they propose to extend these studies of stream and lake sediments into the two additional sub-basins which feed the Mystic Lakes proposed for study in the hydrogeology projects 1-6. The proposal includes obtaining mutational spectra from human cell cultures exposed to raw river sediments, chromate and chromate/arsenite mixtures. Long-term low dose protocols will be used to recreate the conditions calculated to have existed in children drinking the contaminated water from wells G and H. This project combined with the core laboratory and project 1 is responsible for identifying human mutagens in the Aberjona basin. Short term tests are carried out on sediments and the mutagens identified. As chromate and arsenite have been identified in well water, the influence of these and other mutagenic compounds are to be tested in human cell cultures. The wells providing drinking water for Woburn MA residents contain 4uM chromate and 1 uM in arsenite in the period 1964 - 1979. The specific aims of this project is to determine the biological meaning of exposure to such chemicals.